Is there a good standard for threading certain muzzle diameters with a certain threading size?

For instence, a gun I'm having built has a Brux #5 contour and it'll be threaded to a 5/8-24 for my Harvestor. I also have a Rem700 22-250 which I believe has the varmint contour that I was hoping to get threaded for the same can. Although I havent gotten around to measuring the diameter of that barrel (22-250) just yet, it got me to thinking about other guns/barrel contours.

Is one to assume that as long as the diameter of the barrel is larger than the major diameter of the threads, then its good to go with that particular thread size?

Correct. And you need to make sure you have enough of a shoulder left for the brake/suppressor to bud up to. For example, the 5/8"x24 is .625" wide. Your Brux #5 contour barrel should be .700" at the muzzle. This leaves .075" of a shoulder for the muzzle brake or suppressor to bud up to. How much shoulder is needed for reliable threading? Not sure. That's a gunsmith question. But figuring out your muzzle threading depends on the caliber and how much meat (muzzle diameter) is on the muzzle to thread and still have enough shoulder to attach your device.

Correct. And you need to make sure you have enough of a shoulder left for the brake/suppressor to bud up to. For example, the 5/8"x24 is .625" wide. Your Brux #5 contour barrel should be .700" at the muzzle. This leaves .075" of a shoulder for the muzzle brake or suppressor to bud up to. How much shoulder is needed for reliable threading? Not sure. That's a gunsmith question. But figuring out your muzzle threading depends on the caliber and how much meat (muzzle diameter) is on the muzzle to thread and still have enough shoulder to attach your device.

Good info. The red is what I was trying to ask, you just put it in much better words. Thanks.

Obviously to a certain extent, bigger is better, but anyone know of what a good minimum shoulder should be? Although I'm sure Chad already knows, but that 0.075 is total. 0.0375" would be each side. Just a little fyi to others.

The brux is already threaded at 5/8-24. I was just bored and got to thinking about my wifes gun. I've thought of a thread adapter, but i still like the idea of a tighter twist barrel for her 22-250, and it gives me an excuse for it haha

Most common barrel contours on a standard hunting rifle is about a "standard sporter" size barrel, about a #2 contour (or a #3, depending on who's contour chart). 5/8"x24 is too big, so most go to a 9/16" threading. A lot of factory barrels run this size threading.